The conjugated state of estrogen metabolites will be investigated in the bile of female rats injected with various tritiated estrogens and their sulfates. The analyses will be carried out at several time periods after injection. Conjugates will be resolved on alumina columns and the estrogen metabolites in each conjugated group (unconjugated, 3- sulfate, 17 beta-sulfate, 3,17 beta-disulfate, 3-sulfate-16 alpha- glucosiduronate, and the glucosiduronates) analyzed after hydrolysis on thin-layer chromatography and gas-liquid chromatography. Similarly, we shall analyze the plasma estrogens following injection of labeled estrogens or estrogen sulfates into rats with and without bile duct ligation and into rats with partial hepatectomy. Investigation of the para-endocrine phenomena of sulfation of estrogen and estrogen precursors will be carried out in the normal rat mammary gland, in preneoplastic nodules, and in hormone dependent and independent rat mammary tumors. The sulfation rate for each estrogen and estrogen precursor will be determined in the microsome-free supernatant from the above tissues. Each tumor or preneoplastic nodule utilized will be characterized as to its content of estrogen receptor.